Because London Broil is not a tender cut of beef, it is best cooked less rather than more.
1 1/2-inch thick top round London Broil
3/4 cup oil
1/4 to 1/2 cup soy sauce
2 Tbs. white vinegar
1/4 cup honey
1 1/2 tsp fresh ginger
1 tsp. garlic powder
3 green onions, cut up
Using a pointy fork or skewer, stab the London Broil all over to allow the marinade to penetrate the meat and help tenderize it.
I have cooked the London Broil in the broiler with the rack 5-7-inches from the top broiler unit, low broiler setting and broiled 8-10 minutes on the first side and then 5-7 on the other side. Allow to rest 10 minutes before slicing very thin on the diagonal.
Leftovers make delicious fajitas. Top with sauteed onions and bell peppers, add salsa, sour cream, green onions and cheese. A great leftover meal!